Generally, a portable terminal device such as a cell phone includes a liquid crystal display, and various kinds of information are displayed on its display area. If the display area is large, a large amount of information (such as texts) can be displayed at a time, and a television pictures can be displayed in a large size. If the display area becomes large, however, a size of the device itself is increased and the device increased in size is prone to bother the user when carried.
In view of such circumstances, the following configuration, for example, can be employed: a cell phone includes two display areas, and it is possible to switch between a state where the display areas are superposed one above the other and a state where the display areas are laterally arranged side by side. According to this cell phone, when the two display areas are superposed one above the other, since the device body becomes smaller, the cell phone is less prone to bother the user when carried. When the two display areas are arranged side by side upon its use, an image can be displayed on the large screen.